In my experience when I've been playing any system for a long time and my players say "hey do something different" they are almost always looking for something very different from what we are all playing. I've spent the most amount of time playing Mage the Ascension in my rpg career, eventually my current group was hey Mage is getting a bit stale, let's do another game. So we did some Vampire the Masquerade, and it was too close in flavor to Mage. So we started playing some Pathfinder and that was the breath of fresh air we were looking for. Eventually we did switch back to mage, but one of my players decided to run their own campaign set in Star Wars which was a ton of fun.
So forgive me for using my own experience of when my players have asked to play something different my understanding is they are looking for something more drastic that going from one Tolkien inspired fantasy game to another Tolkien inspired fantasy game or from one modern Gothic punk game with magic to another modern Gothic punk game with fangs.
The Technocratic Union are the primary antagonists to the 9 Traditions. No so much purely evil for the sake of evil but a well funded highly authoritarian secret society ideologically opposed to the Traditions. The Technocracy brought us modern plumbing, vaccination and modern medicine, toilet paper, and nuclear weapons, advanced bioweapons, capitalism, and the prison industrial complex.
The Nephandi are the evil for evil sake mages. They are seeking to spread as much pain and misery and bring in the descent of humanity into destruction.
And then there's the marauders, mages who's magickal hubris gets the better of them and they succumb to a reality warping madness.